Quantitative proteomics explores the potential targets and action mechanisms of hydroxychloroquine

Hydroxychloroquine (HCQ) is an autophagy inhibitor that has been used for the treatment of many diseases, such as malaria, rheumatoid arthritis, systemic lupus erythematosus, cancer, and so on. Despite the therapeutic advances in these diseases, the underlying mechanisms have not been well determined and hinder the rational use of this drug in the future. Here, we explored the possible mechanisms and identified the potential binding targets of HCQ by performing quantitative proteomics and thermal proteome profiling on MIA PaCa-2 cells. This study revealed that HCQ may exert its functions by targeting or regulating the expression of some autophagy-related proteins, such as galectin-8 (LGALS8), mitogen-activated protein kinase 8 (MAPK8), Ribosyldihydronicotinamide dehydrogenase (NQO2), Transport protein Sec23A (SEC23A), and so on. Furthermore, HCQ may prevent the progression of pancreatic cancer by regulating the expression of Nesprin-2 (SYNE2), Protein-S-isoprenylcysteine O-methyltransferase (ICMT) and Cotranscriptional regulator FAM172A (FAM172A). Therefore, these findings not only identify potential binding targets for HCQ but also revealed the non-canonical mechanisms of HCQ that may contribute to pancreatic cancer treatment.